功率自适应ld开关电源设计

河南大学 硕士学位论文 功率自适应LD开关电源的设计 姓名：陈瑞霞 申请学位级别：硕士 专业：检测技术与自动化装置 指导教师：毛海涛 2011-05 摘 要 I 摘 要 本文设计了一种稳压型宽范围的开关半导体激光器（LD）的驱动电源，利用单片 机进行自动调节开关电源的绝缘门极晶闸管（IGBT）的占空比，从而使电源输出稳定 的电压来实现 LD 的恒流驱动。该电源还能够据不同规格 LD 在某一定的范围内进行功 率自适应的调节。以单片机为控制核心，结合外围电路，采用 PID 算法实现了 LD 的功 率自适应调节和恒流驱动。即它是一种基于开关电源的并且有功率自适应的功能的 LD 驱动电源，经实验证明，该驱动电路效率高、纹波系数低，且光功率的输出稳定度小于 0.5%，满足了 LD 的实际工作需要。 该设计采用了单片机的控制， 其接收的数据经 A/D 转换后， 再与设定参数进行比较， 然后把得到的处理结果送至 D/A 转换器，来控制 LCD 显示器和键盘等电路，从而实现 了系统的可控化。硬件电路设计运用了模块设计的方法，主要包括了 V/I 转换模块、恒 流源模块、D/A 转换器模块、以及采样模块。本论文的主要研究内容如下： （1）介绍了 LD 的优点、发展史及其主要的应用，并深入研究了 LD 的工作原理， 详细阐述其损坏机理和预防措施。 （2）介绍了开关电源的应用与发展，详细阐述了开关电源的工作原理，并介绍了 几种开关电源的典型主电路，对他们进行优缺点的比较。 （3）根据半导体激光器对电源的要求，设计出一种新型的基于开关电源的具有功 率自适应功能的半导体激光器（LD）驱动电源，该设计采用开关电源做为激光器的驱 动，且可实现功率自适应。 （4）设计系统中硬件模块电路，包括功率采样电路，V/I 转换电路、D/A 电路以及 慢启动电路，并对它们进行分析。设计了温度控制单元和保护电路，详细阐述了系统的 抗干扰措施。 （5）对控制核心单片机及其特点进行了详细阐述，并对与其连接的外围模块电路 进行了分析设计。 （6）介绍了自适应控制程序设计，根据软件设计要求和各个功能子程序的实现方 功率自适应 LD 开关电源的设计 II 法，提供了精确的 PID 控制算法。 （7）对电路的原理图和测试结果进行实验分析，得出结论。 关键词：半导体激光器，开关电源，功率自适应，PID 算法 ABSTRACT III ABSTRACT With its small size, low price and high efficiency, good reliability, long working life and excellent color adjustable feature ，Laser diode (LD) is more widely used in national defense, scientific research, medical, processing and other fields. With the wide spread application of semiconductor laser, its drive power requirements are increasing. The traditional power semiconductor lasers are generally driven by linear power supply, while this kind of bulky power has conversion efficiency and low power consumption. Therefore, the use of switching power supply which has been developed as the drive power of emiconductor laser e shows its more advantage. Traditional LD asks the drive power to provide the corresponding constant current drive according to its own different requirements of to realize his stable power output.If you want to provide different specifications of the LD power-driven, we need to change the output of the adjustment drive power power.Then, the accuracy is not only difficult to control, but also let the work itself becomes complicated. A design of laser Diode (LD) driver based on switching power supply with power adaption is introduced, which uses the single chip microcomputer as control center, combined with external hardware system and PID algorithm, can realize the constant current drive and power adaptive adjustment of the LD by changing the insulated gate bipolar transistor (IGBT) duty cycle of switching power supply. As the experiment results show, this drive circuit has a low ripple factor, high efficiency, and the stability of optical power output is better than 0.5%, which can meet the practical needs of LD. This design uses a microcontroller to receive data through the A/D conversion, and compared with the parameters set, then the results are sent to the D/A converters, control the interface circuit like LCD display and keyboard, and the controllability of the system has been realized. The module design method is used in the hardware Circuit design, and there are constant current source circuit, V/I conversion circuit, power sampling circuit, and the D/A converter circuit. And in connection with the delicate nature of the semiconductor laser, we also designed specifically to add the protection of electrical, temperature control unit and a soft-start circuitry to ensure the semiconductor laser work stablely, accurately, reliablely and 功率自适应 LD 开关电源的设计 IV safely. The main contents of this paper are as follows: (1) Describes the advantages of semiconductor lasers, development history, applications, and the research status of semiconductor laser drive power home and abroad, and we have a general understanding. This thesis discusses the content and significance. Carry out a depth study of the working principle of semiconductor lasers, the system describes the failure mechanism of the semiconductor laser and obtaines notes when using the semiconductor laser. (2) Introduces the application and development of switching power supply, describes the working principle of switching power supply in detail, and introduces several typical main switching power supply circuit and then compares their advantages and disadvantages. (3) According to the requirements of the semiconductor lasers power, designes a new switching power supply with power-based adaptive function of laser diode (LD) drive power, the design uses a switching power supply as a laser driver, and power adaptive can be realized. (4)Designes hardware module circuit in the system, including the power sampling circuit, V/I conversion circuit, D/A circuits and the slow-start circuit, then analyzes them. Designes temperature control unit and the protection circuit, then describes the anti-jamming measures of the system in detai. (5) Studyes the control core microcontroller and its features in detail, and designes and analysises the connection circuit of D/A, display, keyboard, including a simple introduction to the use of the device. (6)